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Finding the Fourth Proportional to 100.63, 138.86 and 56.97

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Solution

The fourth proportional to 100.63, 138.86 and 56.97 is: 78.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.63 : 138.86 = 56.97 : x
  2. Step 2: Convert to fraction form
    100.63/138.86 = 56.97/x
  3. Step 3: Cross multiply
    100.63x = 138.86 × 56.97
  4. Step 4: Simplify right side
    100.63x = 7,910.85
  5. Step 5: Solve for x
    x = 7,910.85/100.63
  6. Step 6: Final answer
    x = 78.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.